|Equals 3 sticker|
It's actually an easy answer.
Let's take Ray William Johnson counting only equals 3, he has other channels (for example breaking NYC) but we will get to that later.
Focusing on equals 3 Ray gets about 2 million views per day, give or take,, so if you take that and see the average YouTube income for each 1.000 views you will see that he makes about 4.000$ per day in average.
If you just take those 4.000$ per day and check it for a year you will get something like 1,5 million per year.
Now once again you have to take in account that he has some expenses with producers and other staff, if you take in account that 50% of the income can pay for those expenses you'll get something like 750.000$ per year.
Also i am not counting merchandise, just one channel (equals 3)
This is a relatively simple and realistic simulation, it may go around that value, you should always think about the expenses that he has to create his content, he is not alone, still he is making money doing what he likes to do, not many people can say that.
If you don't know him, here's the link to this channel: Equals 3